/* Site standard: reset, color tokens (light + dark), and shared components.
   Pages add a small stylesheet of their own only for what is unique to them. */

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* Each color token is light-dark(light, dark); the active side follows color-scheme. */
:root {
  color-scheme: light dark;
  --bg: light-dark(#f5f5f7, #0d1118);
  --surface-muted: light-dark(#fbfbfd, #111722);
  --ink: light-dark(#101114, #e9eef9);
  --muted: light-dark(#505362, #afb8cb);
  --line: light-dark(#d9dce6, #2b3446);
  --blue: light-dark(#0071e3, #409cff);
  --blue-hover: light-dark(#0062c3, #66adff);
  --bg-accent-1: light-dark(rgb(0 113 227 / 18%), rgb(80 130 206 / 22%));
  --bg-accent-2: light-dark(rgb(217 224 238 / 38%), rgb(74 87 116 / 34%));
  --bg-bottom: light-dark(#eff2f6, #111823);
  --topbar-border: light-dark(rgb(210 215 230 / 80%), rgb(73 88 117 / 68%));
  --topbar-bg: light-dark(rgb(255 255 255 / 72%), rgb(18 25 37 / 75%));
  --card-grad-a: light-dark(rgb(255 255 255 / 95%), rgb(25 34 49 / 95%));
  --card-grad-b: light-dark(rgb(245 248 255 / 88%), rgb(17 25 38 / 88%));
  --chip-bg: light-dark(rgb(255 255 255 / 86%), rgb(19 28 43 / 82%));
  --eyebrow: light-dark(#4a5a7a, #9fb1cd);
  --soft-hover: light-dark(#e8eef9, #202e46);
  --font-body: "Public Sans", "Segoe UI", sans-serif;
  --font-display: "Sora", "Public Sans", sans-serif;
  --radius-xl: 2rem;
  --radius-md: 1.1rem;
  --content: min(1120px, calc(100% - 2rem));
  --grid-min: 250px;
}

/* scripts/index-theme.js sets data-theme on body, overriding the system preference. */
body[data-theme="light"] {
  color-scheme: light;
}

body[data-theme="dark"] {
  color-scheme: dark;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  color: var(--ink);
  background:
    radial-gradient(circle at 20% -5%, var(--bg-accent-1), transparent 35%),
    radial-gradient(circle at 90% 0%, var(--bg-accent-2), transparent 38%),
    linear-gradient(180deg, var(--surface-muted) 0%, var(--bg) 46%, var(--bg-bottom) 100%);
  min-height: 100vh;
  line-height: 1.5;
  transition: background-color 220ms ease, color 220ms ease;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
  height: auto;
}

main {
  width: var(--content);
  margin: 1.25rem auto 2rem;
}

/* Top bar */
.topbar {
  width: var(--content);
  margin: 0.75rem auto 0;
  padding: 0.8rem 1rem;
  border: 1px solid var(--topbar-border);
  border-radius: 999px;
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  background-color: var(--topbar-bg);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.75rem;
  position: sticky;
  top: 0.5rem;
  z-index: 20;
}

.brand {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: 0.03em;
  color: var(--ink);
}

.topnav {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.topnav a {
  color: var(--ink);
  font-weight: 600;
  padding: 0.48rem 0.78rem;
  border-radius: 999px;
}

.topnav a:hover {
  background: var(--soft-hover);
}

.theme-toggle {
  border: 1px solid var(--line);
  color: var(--ink);
  background-color: var(--chip-bg);
  font: inherit;
  font-weight: 700;
  padding: 0.46rem 0.8rem;
  border-radius: 999px;
  cursor: pointer;
  transition: transform 160ms ease, background-color 160ms ease;
}

.theme-toggle:hover {
  transform: translateY(-1px);
  background-color: var(--soft-hover);
}

/* Hero panel */
.hero {
  border: 1px solid var(--line);
  border-radius: var(--radius-xl);
  background: linear-gradient(145deg, var(--card-grad-a), var(--card-grad-b));
  box-shadow: 0 16px 34px rgb(16 34 56 / 10%);
  padding: 1.3rem;
}

.hero h1 {
  margin-top: 0.4rem;
  font-family: var(--font-display);
  font-size: 2.05rem;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.eyebrow,
.card-kicker {
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  color: var(--eyebrow);
  font-weight: 700;
}

.card-kicker {
  font-size: 0.76rem;
  letter-spacing: 0.14em;
}

.subtitle {
  margin-top: 0.9rem;
  color: var(--muted);
  max-width: 68ch;
  line-height: 1.6;
}

.subtitle a,
.site-footer a {
  color: var(--blue);
  font-weight: 700;
  text-decoration: underline;
  text-underline-offset: 0.14rem;
}

.hero-actions {
  margin-top: 1.1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

/* Buttons */
.btn {
  padding: 0.7rem 1rem;
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.95rem;
  transition: transform 160ms ease, box-shadow 160ms ease, background-color 160ms ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background-color: var(--blue);
  color: #fff;
  box-shadow: 0 8px 20px rgb(0 113 227 / 30%);
}

.btn-primary:hover {
  background-color: var(--blue-hover);
}

.btn-ghost {
  border: 1px solid var(--line);
  background-color: var(--chip-bg);
  color: var(--ink);
}

/* Card grid: a page tunes the column width with --grid-min. */
.grid {
  margin-top: 1.4rem;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(var(--grid-min), 100%), 1fr));
  gap: 1rem;
}

.card {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 1rem;
  overflow: hidden;
  background: linear-gradient(165deg, var(--card-grad-a), var(--card-grad-b));
  box-shadow: 0 10px 24px rgb(13 26 42 / 8%);
  transition: transform 180ms ease, box-shadow 180ms ease;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: 0 14px 30px rgb(13 26 42 / 14%);
}

.card h2 {
  margin-top: 0.35rem;
  font-family: var(--font-display);
  font-size: 1.28rem;
  line-height: 1.2;
}

.card p {
  margin-top: 0.5rem;
  color: var(--muted);
}

.card img {
  display: block;
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.site-footer {
  width: var(--content);
  margin: 0 auto 1.2rem;
  text-align: center;
  color: var(--muted);
  font-size: 0.9rem;
}

@media (max-width: 759px) {
  .topbar {
    border-radius: 1.25rem;
    flex-wrap: wrap;
    justify-content: center;
  }

  .brand {
    flex: 1 1 100%;
    text-align: center;
  }

  .topnav {
    width: 100%;
    justify-content: center;
    flex-wrap: wrap;
    gap: 0.45rem;
  }

  .topnav a,
  .theme-toggle {
    padding: 0.42rem 0.62rem;
    font-size: 0.9rem;
  }
}

@media (min-width: 760px) {
  .topbar {
    margin-top: 0.9rem;
    padding: 0.9rem 1.1rem;
  }

  .hero {
    padding: 1.8rem;
  }

  .hero h1 {
    font-size: 3rem;
  }

  .subtitle {
    font-size: 1.06rem;
  }

  .card {
    padding: 1.15rem;
  }
}

@media (min-width: 1120px) {
  .hero h1 {
    font-size: 3.6rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition: none !important;
  }
}